A Kansas City Chiefs fan holds a sign during the first half of an NFL football game against the Carolina Panthers at Arrowhead Stadium in Kansas City, Mo., Sunday, Dec. 2, 2012. The Chiefs' ended an eight-game losing streak with a 27-21 victory over the Panthers just a day after their linebacker Jovan Belcher shot his girlfriend multiple times at a residence near the stadium. He then drove to the team's practice facility and turned the gun on himself as general manager Scott Pioli and coach Romeo Crennel looked on. (AP Photo/Colin E. Braley)

KANSAS CITY, Mo. (AP) — As investigators search for a motive to help explain why Chiefs linebacker Jovan Belcher killed his girlfriend and then himself, a discordant picture of the couple began to emerge.

Belcher and his girlfriend, 22-year-old Kasandra M. Perkins, had lived apart briefly earlier in the year but had gotten back together by Thanksgiving, according to a friend of Perkins.

Brianne York, 21, said Sunday the couple, who had a 3-month-old daughter, Zoey, argued about "normal couple stuff" but that her friend was "really happy about being a mom."

When she learned Saturday that Belcher had fatally shot Perkins at the couples' home, York said, she thought someone must have been mistaken.

Afterward, Belcher drove about five miles to Arrowhead Stadium, where he thanked general manager Scott Pioli and coach Romeo Crennel for all they'd done for him. Belcher then fatally shot himself in the practice facility's parking lot, police said.

Sunday found Crennel on the sidelines, bravely holding together a team in turmoil. The Chiefs rallied to a 27-21 victory over the Carolina Panthers, breaking an eight-game losing streak.

"It was tough," said quarterback Brady Quinn. "It was an eerie feeling after a win, because you don't think you can really win in this situation."

York, who met Perkins while taking classes at the Blue River campus of Metropolitan Community College, said the women bonded during their pregnancies. York has a baby boy who was born months before Perkins gave birth to Zoey.

"It doesn't seem that that would be the end of their story," York said. "It just seems like if things didn't work out, they would have gone their separate ways. I would never have thought that this would be how it ended."

York said that sometime after Halloween Perkins had gone to visit her family in Texas. Perkins also briefly stayed with her cousin, who is married to Chiefs player Jamaal Charles. Belcher and Perkins met through Charles, York said.

A message left for Charles and his wife through an assistant was not immediately returned.

York said the root of the argument was that Belcher, "sometimes he would just be down in his man cave or whatever," and Perkins wanted to spend more time together as a family.

"They ended up wanting to try to work it out," York said, "and the next time I went over and visited she told me everything was good and things were better, so I thought everything was fine."

Kansas City police spokesman Darin Snapp reiterated Sunday that the couple had argued recently but he could provide no additional details.

At the couple's former home, people could be seen coming and going Sunday. "Can you all respect grieving?" said a man who answered the door at the couple's home. A short time later, at the same time the Chiefs were playing, two men loaded bags into a car, and two women drove away.

Attempts to reach various members of Perkins' family in Austin, Texas, were unsuccessful.

Neighbors in the newly built Kansas City subdivision where the couple had lived since April were stunned by Saturday's violent events.

Kristen VanMeter, 31, lives near the couple and said also she had taken community-college courses with Perkins. VanMeter said the couple threw "a lot of parties" but said she heard nothing unusual the morning of the killing.

"It's a surprise," she said. "There had to of been something that triggered it."

Belcher's mother, who was staying with the couple, called 911 after her son shot Perkins. Snapp said 911 tapes are not public records in Missouri.

Shawn Martin, vice president of the neighborhood homeowners association, said she wasn't aware of any problems that preceded the shooting.

She described the parties at the home Belcher and Perkins shared as "nothing more than any other young couple" would have.

After having the baby, Perkins was taking the fall semester off school. York said Perkins planned to return in January and wanted to become a teacher.

Police said Belcher's mother was living with the couple, but York said she just made frequent visits, sometimes lasting a couple weeks at a time. She doesn't know who will care for the baby now.

"They just seemed really happy around each other, and I just don't understand where things went wrong," York said.

York said the only other stress Perkins mentioned was whether Belcher would stay with the Chiefs.

"She was a really good person to be around and a lot of fun," York said. "She was somebody you could call when you were down and she would talk you through it. She would lift you back up and make you feel happy again if you were sad or upset."